<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        {{arr}}
        {{obj}}
        <button @click="change()">改</button>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                arr: [1,2,3,4,5],
                obj:{
                    id:1
                }
            },
            methods:{
                change(){
                    // this.arr[1]=56
                    // this.obj[dd]=2
                    this.$set(this.obj,'dd',2)
                    this.$set(this.arr,1,2)
                }
            }
        })
    </script>
</body>
</html>